This invention relates generally to electrical control devices and in particular to electrical switches and methods of operating an electrical switch.
In the past, various and sundry electrical switches have been provided for controlling or completing a plurality of circuits therethrough, and different modes of manually operating such electrical switches have been employed therewith. For instance, some of the more well known manual operating modes or actuating devices commonly employed with the prior art electrical switches were of the push button type, the toggle type, the slide type, and the rotary type including those with motion translating means, all of which are well known in the art.
With respect to at least some of the prior art rotary-type operated electrical switches, a cam having a predetermined cam configuration on one face thereof was rotated so that the cam configuration selectively operated a plurality of switch blades in following engagement therewith for respectively completing a circuit through the switch. At least one of the disadvantageous or undesirable features of this particular prior art rotary-type electrical switch is believed to be that the number of switch blades utilized dictated the size of the cam necessary to effect the selective operation thereof, i.e., the more switch blades utilized, the greater the size of the cam. Of course, an analogous disadvantageous or undesirable feature is believed to be that of the economics involved in providing larger cams to accommodate the greater number of switch blades.
In at least others of the prior art rotary-type operated electrical switches, a cam having a peripheral face with a plurality of cam configurations therein was rotated so that the cam configurations selectively operated a plurality of switch blades arranged adjacent the peripheral face of the cam in following engagement therewith for respectively completing a circuit through the switch. At least one of the disadvantageous or undesirable features of this particular prior art rotary-type electrical switch is believed to be that the space occupied by the various switch blades arranged adjacent the peripheral face of the cam for operation thereby appreciably limited the number of switch blades that could be employed in the switch.
Another similar prior art rotary-type operated electric switch contained a plurality of cams arranged generally in side-by-side relation, each having a peripheral face with a plurality of cam configurations therein, and a plurality of switch blades were arranged adjacent the peripheral face of each cam in following engagement therewith for respectively completing a circuit through the switch. In addition to the limited number of switch blades that could operably be employed peripherally about each cam, as previously mentioned, it is believed that at least another disadvantageous or undesirable feature of this particular prior art rotary-type electrical switch involved the consequential enlargement of the switch as additional cams were added in their side-by-side relation.
Further, in others of the prior art rotary-type electrical switches, a generally elongate stationary plate was provided with a plurality of contacts thereon, and another generally elongate scanner plate having a plurality of switch blades thereon was moved lengthwise and crosswise of the contact carrying plate to selectively engage the switch blades with the contacts for respectively completing circuits through the switch. A cam having a peripheral face defining a predetermined cam configuration was rotated to drivingly engage its peripheral face with a pair of follower posts on the scanner plate to impart the lengthwise and crosswise movement thereto. At least one of the disadvantageous or undesirable features of this particular prior art rotary-type electrical switch is believed to be that the driving engagement of the cam only with the scanner plate, at least in part, inhibited the motion translating capacity of device.